A serial number is a unique number that is one of a series assigned for identification which varies from its successor or predecessor by a fixed discrete integer value. Common usage has expanded the term to refer to any unique alphanumeric identifier for one of a large set of objects, however in data processing and allied fields in computer science. Not every numerical identifier is a serial number; identifying numbers which are not serial numbers are sometimes called nominal numbers. A number is an abstract entity that represents a count or measurement. ... A successor function is the label in the literature for what is actually an operation. ... This page is a candidate for speedy deletion. ... The integers are commonly denoted by the above symbol. ... Generally speaking, the term alphanumeric refers to anything that consists of only letters and numbers. ... In mathematics, a set can be thought of as any collection of distinct things considered as a whole. ... Data processing is any computer process that converts data into information or knowledge. ... Computer science, or computing science, is the study of the theoretical foundations of information and computation and their implementation and application in computer systems. ... Nominal numbers are numbers used for identification only. ...

Sequence numbers are almost always non-negative, and typically start at zero or one.

Applications of serial numbering

Serial numbers are valuable in quality control, as once a defect is found in the production of a particular batch of product, the serial number will quickly identify which units are affected. Serial numbers are also used as a deterrent against theft and counterfeit products in that serial numbers can be recorded, and stolen or otherwise irregular goods can be identified. There are many different numbering schemes for assigning numbers to entities. ... In engineering and manufacturing, quality control and quality engineering are involved in developing systems to ensure products or services are designed and produced to meet or exceed customer requirements. ...

Many computer programs come with serial numbers, often called "CD keys," and the installers often require the user to enter a valid serial number to continue. These numbers are verified using a certain algorithm to avoid usage of counterfeit keys. In mathematics, computing, linguistics, and related disciplines, an algorithm is a finite set of well-defined instructions for accomplishing some task which, given an initial state, will terminate in a defined end-state. ...

Serial numbers also help track down counterfeit currency, because in some countries each banknote has a unique serial number. For other uses, see Counterfeit (disambiguation). ... A £20 Bank of England banknote. ...

The ISSN or International Standard Serial Number seen on magazines and other periodicals, an equivalent to the ISBN applied to books, is serially assigned but takes its name from the library science use of serial to mean a periodical. ISSN, or International Standard Serial Number, is the unique eight-digit number applied to a periodical publication including electronic serials. ... The International Standard Book Number, or ISBN (sometimes pronounced is-ben), is a unique[1] identifier for books, intended to be used commercially. ... Library science is the science and study of issues related to libraries and the organization and management of information resources. ...

Certificates and Certificate Authorities (CA) are necessary for widespread use of cryptography. These depend on applying mathematically rigorous serial numbers and serial number arithmetic In cryptography, a certificate authority or certification authority (CA) is an entity which issues digital certificates for use by other parties. ... The German Lorenz cipher machine, used in World War II for encryption of very high-level general staff messages Cryptography (or cryptology; derived from Greek κρυπτός kryptós hidden, and the verb γράφω gráfo write) is the study of message secrecy. ...

The term "serial number" is also used in military formations as an alternative to the expression "service number". A service number is a identification code used to easily identify a person within a large group. ...

Serial number arithmetic

Main article: Serial Number Arithmetic

Serial numbers are often used in network protocols. However, most sequence numbers in computer protocols are limited to a fixed number of bits, and will wrap around after a sufficiently many numbers have been allocated. Thus, recently-allocated serial numbers may duplicate very old serial numbers, but not other recently-allocated serial numbers. To avoid ambiguity with these non-unique numbers, RFC 1982, " Serial Number Arithmetic" defines special rules for calculations involving these kinds of serial numbers. There are very few or no other articles that link to this one. ... In networking, a communications protocol or network protocol is the specification of a set of rules for a particular type of communication. ...

Lollipop sequence number spaces are a more recent and sophisticated scheme for dealing with finite-sized sequence numbers in protocols. ...

References

• William W. Plummer, "Sequence Number Arithmetic" BB&N Inc, September 1978.
• R. Elz and R. Bush, RFC 1982, "Serial Number Arithmetic" Network Working Group, August 1996

See also

• Cardinal number
• Ordinal number
• Nominal number
• Numbering scheme
• Lollipop sequence

Aleph-0, the smallest infinite cardinal In mathematics, cardinal numbers, or cardinals for short, are a generalized kind of number used to denote the size of a set. ... Commonly, ordinal numbers, or ordinals for short, are numbers used to denote the position in an ordered sequence: first, second, third, fourth, etc. ... Nominal numbers are numbers used for identification only. ... There are many different numbering schemes for assigning numbers to entities. ... ...

External links

• ISSN Home page